1. Field of the Invention
The present invention relates to a display device.
2. Description of the Related Art
An MEMS display (Micro Electro Mechanical System Display) is a display which is expected to take the place of a liquid crystal display (see JP 2008-197668 A). This display, unlike a liquid-crystal shutter type display which makes use of polarization, displays a tone by mechanically opening or closing a light transmitting window using a shutter unit having a shutter. To be more specific, the shutter having a drive aperture is arranged above a light blocking film where a fixed aperture is formed.
Further, in the structure shown in JP 2008-197668 A, the shutter is configured to be driven by an electrostatic force generated between a first beam and a second beam. One end of the first beam is connected to the shutter, and the other end of the first beam is fixed to an anchor portion. The shutter is moved as the first beam is deformed about a fixing point.
The shutter is configured to be driven by being arranged with a gap between the shutter and a light blocking film, and when the fixed aperture and the drive aperture communicate with each other, light which advances perpendicular to a screen passes through the fixed aperture and the drive aperture. On the other hand, light which obliquely advances through the fixed aperture is blocked by the shutter even when the fixed aperture and the drive aperture communicate with each other. When the fixed aperture and the drive aperture are elongated, light which advances obliquely along the longitudinal direction passes through the drive aperture, light which advances obliquely along the lateral direction runs off from the drive aperture and is blocked by the shutter. Accordingly, there exists a drawback on a field-of-view characteristic that the brightness differs depending on the viewing direction.
Further, in the structure shown in JP 2008-197668 A, although first beams extend from opposing sides of the rectangular shutter, on each one side of the shutter, a pair of first beams extends in the directions opposite to each other along the side from the center portion. Accordingly, a length of one first beam is short, that is, one half or less of a length of one side. Further, a length of the second beam is also short corresponding to the length of the first beam so that an electrostatic force between the first beam and the second beam is decreased. Still further, the rigidity of the shutter between the first beam and the second beam is increased and hence, there arises a drawback that it is difficult to move the shutter and thereby a movable distance of the shutter becomes short, or it is necessary to increase the potential difference between the first beam and the second beam to move the shutter a desired distance.